grainstretch~by Timo Rozendal
Flexible realtime timestretching and pitchshifting with a granular engine in Max/MSP.
With this external you can expand your max toolkit for natural and experimental playback. It incorporates the algorithm used by Mattijs Kneppers in his granular stretcher patch and adds a load of extra options and features.
It is available for both windows and mac, and works in max 5 (in 32bit) and max 6 (in 64 bit).
The video below gives you an impression of what you can do with it by giving you a walkthrough using the helpfile: